Thermal unit



April 23, 1963 c. B. SPASE 3,086,398

THERMAL UNIT Original Filed May 13, 1958 INV EN TOR BY QZLLQ new V ATTORNEY 3,086,398 THERMAL UNl'l Charles B. Spase, Syracuse, N.Y., assiguor to Lipo- Rollway Corporation, dyracuse, N.Y., a corporation of New York Original application May 13, 1953, Ser. No. 734,944, new Patent No. 2,924,083, dated Feb. 9, 1960. Divided and this application Aug. 21 1959, tier. No. 337,317

2 Qlairns. (Cl. 73-4968) The present invention relates to a thermally responsive device that expands in one direction upon being heated and is strong enough to transmit forces at right angles to the direction of expansion.

Prior art thermal devices have in general either been complicated, expensive, had a low capacity for thermally expansible material in relation to the over-all dimensions of the device or were not suitably rugged for use as a mechanical coupling.

Other known thermally responsive devices have not been able to withstand large shearing forces at right angles to the direction of expansion. As a consequence, they were unsuited for use in torque transmitting devices, as for providing the connection between driving and driven members.

This application is a division of copending application Serial No. 734,944, filed May 13, 1958, which has now issued as United States Letters Patent No. 2,924,083, dated February 9, 1960.

An object of the present invention is to provide a thermally responsive device that will expand upon the application of heat and that is of extremely rugged construction.

Another object of the present invention is to provide a thermally expansive device that has large volume of thermally expansible material in comparison with the total volume of the device, and that is also of strong construction.

Yet another object of the present invention is to provide a thermally expansible device that will exclude all foreign matter and at the same time be of extremely simple and rugged construction.

Other objects and the nature and advantages of the instant invention will be apparent from the following description taken in conjunction with the accompanying drawings, wherein:

The sole FIGURE is a longitudinal cross-sectional view of a thermally responsive device made in accordance with the present invention.

Referring now to the drawings, there is shown in the figure a thermal unit 52 which consists of an outer capsule member 60 that is cup-shaped and has end wall 61 and an open-ended skirt 62 extending therefrom. Telescopically received within the skirt 62 of the capsule member 69 is a plug member 63 having a skirt 64, the skirt 64 having a plurality of circumferentially extending grooves 65 on the exterior periphery thereof. Plug member 63, which is also cup-shaped, has an end wall 66 having a threaded hole 67 therein, and a plug 68 in said hole 67.

The end wall 66 of plug member 63, the end wall 61 of capsule 60, and the interior of the skirt 64 of plug member 63 form a chamber 69 in which there is posiice at; tioned the thermally expansible material 7tl. This material is preferably solid at ordinary temperatures, or room temperatures but becomes liquid at approximately 300 F., and upon further heating of the material 70 above 300 F., the material '76 will expand. Such materials are well known in the art, and the specific material used forms no part of the present invention.

In operation, the thermally responsive unit 52 will transmit rotary forces from, for instance, a driving member engaging one part of capsule to a driven member engaging an axially spaced part thereof. Due to the rugged construction of unit 52, it will hold up through a long period of rough usage. When the thermally responsive device 52. is heated to a temperature of approximately 300 F., the material 76 therein will liquefy, and upon further heating will expand; this will serve to drive the plug member 63 outwardly of the capsule 6t and to expand the skirt 64 outwardly into tight engagement with skirt 62, to exclude dirt or air from chamber 69. The skirt 64 in the area Where the grooves 65 are formed, will be thinned out and thus expansion of the thermal responsive material 76 will tend to urge the relatively thinned out portion of skirt 64 into tight or sealing relationship with the inner surface of skirt 62 of the capsule member 68.

As may be seen, this construction provides for a relatively large amount of thermally responsive material in a given volume of the thermally responsive device 52, so that the volume of the material 70 is relatively large compared to the over-all dimensions of the device 52.

It will be obvious to those skilled in the art that various changes may be made without departing from the spirit of the invention and therefore the invention is not limited to what is shown in the drawings and described in the specification but only as indicated in the appended claims.

What is claimed is:

1. A thermally responsive device comprising an outer capsule member having an end wall and an open-ended skirt extending therefrom, a plug member having a skirt telescopically within the skirt of the capsule member and an end Wall closing off the capsule skirt at one end, said skirt of said plug member having a plurality of circumferentially extending recesses on the exterior thereof, the end wall of the plug member being in juxtaposition with the open end of the skirt of the capsule, and a thermally expansible material between said end Walls and within said skirt of said plug member.

2. A thermally responsive device comprising an outer capsule member having an end wall and an open-ended skirt extending therefrom, a plug member having a skirt telescopically within the skirt of the capsule member and an end wall closing off the capsule skirt at one end, said skirt of said plug member having a plurality of peripheral recesses about the exterior thereof, the end wall of the plug member being in juxtaposition adjacent the open end of the skirt of the capsule, and a thermally expansible material between said end walls and within said skirt of said plug member.

References Jited in the file of this patent FOREIGN PATENTS 394,885 Germany May 12, 1924 

2. A THERMALLY RESPONSIVE DEVICE COMPRISING AN OUTER CAPSULE MEMBER HAVING AN END WALL AND AN OPEN-ENDED SKIRT EXTENDING THEREFROM, A PLUG MEMBER HAVING A SKIRT TELESCOPICALLY WITHIN THE SKIRT OF THE CAPSULE MEMBER AND AN END WALL CLOSING OFF THE CAPSULE SKIRT AT ONE END, SAID SKIRT OF SAID PLUG MEMBER HAVING A PLURALITY OF PERIPHERAL RECESSES ABOUT THE EXTERIOR THEREOF, THE END WALL OF THE PLUG MEMBER BEING IN JUXTAPOSITION ADJACENT THE OPEN END OF THE SKIRT OF THE CAPSULE, AND A THERMALLY EXPANSIBLE MATERIAL BETWEEN SAID END WALLS AND WITHIN SAID SKIRT OF SAID PLUG MEMBER. 